Structure-Dependent Redox Stability and Local Pro-Oxidant Profiles of Anthocyanins Associated with Central and Sympathetic Nervous System Activation

This study aimed to elucidate how B-ring substitution patterns of pelargonidin-3-glucoside (P3G), cyanidin-3-glucoside (C3G), and delphinidin-3-glucoside (D3G) dictate their physicochemical stability and localized redox profiles, and how these chemical traits conceptually associate with downstream behavioral and autonomic responses. Under acidic conditions (pH 2.8), P3G and C3G exhibited >90% retention over 25 h, whereas D3G showed partial degradation (∼70%). Under neutral conditions (pH 7.0), all three anthocyanins degraded, with D3G displaying markedly rapid autooxidation. In xanthine-xanthine oxidase assays, low concentrations (0.2 ) of anthocyanins enhanced O 2 • − -dependent chemiluminescence in the order of . In rodent evaluations, single oral administration of C3G elicited a significant increase in mice spontaneous locomotion, sustained rat cremasteric arterial blood flow, and elevated 24-h urinary catecholamine excretion in mice. Physiological responses followed the identical hierarchy ( ), demonstrating a perfect rank correlation r s = 1.00 with in vitro O 2 • − -promoting profiles. While D3G possesses a high theoretical redox potential, its physiological impact was limited by rapid autooxidation. Conversely, C3G maintained an optimal stability-reactivity window, and its primary B-ring degradant, protocatechuic acid, retained O 2 • − -promoting capacity. Conceptually linking in vitro local redox signaling to in vivo interoceptive gut-brain activation, these findings establish a strong structure-dependent association—rather than a direct causal mechanism—between localized pro-oxidant profiles and autonomic/behavioral responsiveness.